Deep brain stimulation (DBS) devices - `brain pacemakers' - have recently emerged as an exciting novel neurotechnology for treating severe movement disorders, such as Parkinson's Disease and Essential Tremor. Accurate mapping of deep brain regions is necessary to obtain an optimal treatment of DBS with minimal risk to the patient. At present, electrophysiological mapping involves slowly advancing a single-channel microelectrode in small steps in order to record the neural activity in the region of the electrode tip. This process is tedious and time-consuming due to the serial nature of the procedure. The subject of this proposal, the Deep Brain Microelectrode Array (DBMA), is an innovative device that has multiple precisely placed sites along its length which permit simultaneous recording and stimulation at different depths in the brain, leading to more accurate and faster mapping. The DBMA is a modular device that consists of up to 18 recording sites positioned in a bi-linear arrangement such that multiple brain regions spanning 9mm or more may be monitored simultaneously. The basic components of the DBMA are the electrode array and the carrier. The electrode array is a microfabricated device based on polyimide with thin-film metal interconnects and electrode sites. The carrier is comprised of a clinical grade tungsten microelectrode and a polyimide tube. The device has been designed using FDA cleared materials and has the same form factor as a single-channel mapping microelectrode, essentially making it a drop-in replacement for the current device. Specific Aim 1 of Phase II will focus on extending the functionality of the recording array developed in Phase I by adding ring-shaped sites to the device that are suitable for macrostimulation. Manufacturing techniques will be optimized for high volume and clinical device production. Specific Aim 2 will develop a clinical grade multichannel data acquisition and stimulation system for use with the multimodal DBMA. The devices and instrumentation developed and bench tested in Aims 1 and 2 will be validated for use in mapping procedures in animals in Specific Aim 3. The outcome of the project will be a complete deep brain mapping system (i.e., mapping electrodes and instrumentation) ready for pre-clinical evaluation. An animal research version of the system will be ready for commercialization. NeuroNexus, Inc. is leading the project in collaboration with FHC, Inc., the University of Michigan and consultants from the Cleveland Clinic. This multi-disciplinary effort will result in a system positioned to become a key component in the planning and delivery of stereotactic interventions for neurological disorders, which will enable further optimization of current treatments and facilitate new treatments.